Monday, February 24, 2014

Biology: Variation Lab guidesheet 2/23-4

Variation Lab

Pre-Lab Discussion:The members of a
species are not exactly alike. Small differences called variations exist in
each member of a species. Some variations may be passed on to the offspring of
an organism through reproduction. Most inherited variations are neutral; that
is, they do not affect the survival of the organism. Some variations are
helpful. Helpful inherited variations are called adaptations. Harmful inherited
variations will cause the organism to be less well-suited to its environment.

The
process by which organisms with adaptations to the environment survive is
called natural selection. Natural selection tends to allow well-adapted
organisms to reproduce and pass the beneficial trait to their offspring.

After
you have read through the entire handout discuss with your partners
whether you think plants or animals will show a greater degree of
variation.DO NOT just guess your
discussion should include examples and why you think one or the other will
vary more.Doing this will help you
with the Framework and Logic scores on your conclusion; take notes!

Make
a rough draft of the Q, H, T, diagrams, DT; you do not need to include
procedures in your rd or fd.

the
data manipulation section of the rubric will be 3x score (graph=1x &
analysis questions=2x)

Graph
the number of variation measurements (hand spans or blade lengths) vs the
sizes in cm.Make a bar graph for
the plant leaves and hand spans it will look similar to the traits lab
graphs

Question:Will there be a greater degree of variation
in the leaves of a plant species or
in the hand span of Humans?

Procedures
Hand Span variation:make a diagram

1.Place the palm of your hand on a blank piece of paper, with
your fingers spread out as much as possible. Make a mark on the paper at the
top of your thumb and another mark at the top of your little finger is. Don't
include fingernails.

2.Measure your hand span between the two marks with a ruler.
Round off your measurement to the nearest centimeter and record the information
in your data table.

3.Next, gather hand span measurements for everyone in class and
put them into your data table.

Procedures
leaf variation:make a diagram

Obtain a
number of leaves equal to the number of students in class.

Measure the
length of the leaf blades in centimeters. Record the measurements

Depending on
the supply of leaves you may have to share leaves between tables.Try to not measure the same leaf
multiple times.

Analysis Questions

Calculate
standard deviation for each sample by finding the total average of all for
both hands and leaves (separately).Next. Subtract each sample from the average and this is your
“standard deviation- round to nearest whole number!)

Did the number
of hand spans measured in your class influence the shape of the graph? If
you had a much larger sample of hand spans, how do you think the graph
might change?

Would any of
the variations you observed in hand spans be an advantage in terms of the
survival of humans? List two advantages each for larger and smaller hand
spans.